Cognitive Outcome After Off-Pump and On-Pump Coronary Artery Bypass Graft Surgery

Abstract

Context Coronary artery bypass graft (CABG) surgery is associated with a decline in cognitive function, which has largely been attributed to the use of cardiopulmonary bypass (on-pump procedures). Cardiac stabilizers facilitate CABG surgery without use of cardiopulmonary bypass (off-pump procedures) and should reduce the cognitive decline associated with on-pump procedures. Objective To compare the effect of CABG surgery with (on-pump) and without (off- pump) cardiopulmonary bypass on cognitive outcome. Design and Setting Randomized controlled trial conducted in the Netherlands of CABG surgery patients enrolled from March 1998 through August 2000, with 3- and 12-month follow-up. Participants and Intervention Patients scheduled for their first CABG surgery (mean age, 61 years; n=281) were randomly assigned to off-pump surgery (n=142) or on- pump surgery (n=139). Main Outcome Measures Cognitive outcome at 3 and 12 months, which was de- termined by psychologists (blinded for randomization) who administered 10 neuro- psychological tests before and after surgery. Quality of life, stroke rate, and all-cause mortality at 3 and 12 months were secondary outcome measures. Results Cognitive outcome could be determined at 3 months in 248 patients. Cog- nitive decline occurred in 21% in the off-pump group and 29% in the on-pump group (relative risk (RR), 0.65; 95% confidence interval (CI), 0.36-1.16; P=.15). The overall standardized change score (ie, improvement of cognitive performance) was 0.19 in the off-pump vs 0.13 in the on-pump group (P=.03). At 12 months, cognitive decline occurred in 30.8% in the off-pump group and 33.6% in the on-pump group (RR, 0.88; 95% CI, 0.52-1.49; P=.69). The overall standardized change score was 0.19 in the off-pump vs 0.12 in the on-pump group (P=.09). No statistically significant differ- ences were observed between the on-pump and off-pump groups in quality of life, stroke rate, or all-cause mortality at 3 and 12 months.